Switch



p i 1937- R. K. WINNING 2,077,504

SWITCH Filed Sept. 50, 1935 INVENTOR ATTORNEYS Patented Apr. 20, 1937UNITED STATES PATENT OFFHQE SWITCH Robert K. Winning, Wauwatosa, Wis.,assignor to Clum Manufacturing Company,

Milwaukee,

7 Claims.

This invention relates to improvements in switches.

The switch herein disclosed has a specialized function in connectionwith the preselective electro-vacuum gear shifter employed on certaincurrent automobiles. More generally, however, the present switchperforms the function of a reversing switch with a snap action andvarious of its features are usable on switches generally.

It is the primary object of the invention to provide a novel andimproved switch construction, employing a snap action mechanism withlost motion between the actuator and the contact carrier sumcient toassure a substantially complete throw of the actuator before the contactcarrier snaps to its new position. In this connection, it is a furtherpurpose of the invention to provide a simple, inexpensive and effectivetype of snap action mechanism peculiar- 1y adapted to be installed inextremely small and compact form between concentric oscillatory members.

It is a further very important object of the present invention toprovide a novel and simplified form of self-equalizing bridge contactsof such a character that the compression of a single contact spring isdivided between a number of different contacts on the contact carrierand is then divided between the ends of the respective contacts so thatin all positions of the carrier the pressure exerted by the movingcontacts upon the fixed contacts will be substantial at all points.

But for this arrangement, the moving contacts might engage selectedfixed contacts and remain either wholly or partially out of engagementwith other fixed contacts. Due to the novel and simple constructionhereinafter to be disclosed, some portion of the pressure of the singlecompression spring is distributed to effect engagement of all contacts.

In the drawing:

Fig. 1 is a side elevation of the switch as it appears when installed inthe mechanism for which it is specifically adapted.

Fig. 2 shows an interior view of the switch casing as it appears withthe back removed and the moving contact carrier removed to expose thesnap action mechanism.

Fig. 3 is a plan view of the moving contact carrier.

Fig. 4 is an inverted plan view of the fixed contact carrier or switchback.

Fig. 5 is a detail view of the switch in cross 55 section.

Fig. 6 is an enlarged detail view of one of the equalizing bridgecontacts as viewed on the line 6-6 of Fig. 3.

Fig. 7 is a front elevational View of the switch casing.

Fig. 8 is a view similar to Fig. 3 illustrating a modified form ofcontact carrier.

Fig. 9 is a plan view of a modified snap action mechanism.

Fig. 10 is an exploded view, showing in per.

spective the driving head and one of the associated spring guides.

Like parts are designated by the same reference characters throughoutthe several views.

The preselective electro-vacuum gear shifter in which this switch mayfind a specific use is described in the issue of the publicationentitled Automotive Industries and dated December 15, 1934 (vo1.'71, p.732). The switch casing I0 is mounted by means of its flange H in ahousing 12 which forms the cover of a diaphragm chamber l3. Thediaphragm I4 carries a fitting at l5 connected by link Hi to the rockerarm I? which is mounted on the squared end of the rock shaft I8. Thecase is embossed to provide semiconical stops outwardly projecting atit? to limit the movement of oscillation of the lever or rocker arm I1.Similar bosses inwardly projecting at 20 limit the range of oscillationof the contact actuator 25.

The contact actuator 25 oscillates coaxially with shaft l8 beingpreferably mounted loosely upon the shaft and held in place by thecylindrical head 26 fixed at the inner end of the shaft and providedwith longitudinally extending oppositely disposed grooves at 2? for thespring guides of the snap action mechanism. The actuator 25 is in theform of a plate having arcuate upturned end portions at 28 shouldered toprovide a seat for the contact carrier 23 and having lugs30 projectingbeyond its shoulders for engagement in the notches 3! of the contactcarrier.

Each of the end flanges 28 is apertured to receive slidably the rod-likeend of the guide 34 for a compression spring 35. Each of the guides 34has a wide flat terminal portion 36 oppositely notched at 31 andpivotally engaged in one of the grooves 21 of the spool-shaped driverhead 26 on the rock shaft. The shoulder provided by the terminal portionof each spring guide at 38 seats one end of the compression spring 35,the other being seated directly against the upturned flange 28 of theactuating plate 25.

The arrangement is such that the reaction of compression springs in anygiven position of rest of the parts tends to oscillate the rock shaft l8in one direction by pressure of the heads 36 against the sides of thegroove in the rock shaft head member 26. At the same time thecompression of springs 35 is exerted in the opposite direction upon theupturned flanges 28 of the actuator to tend to oscillate the actuatoroppositely to the rock shaft. The actuator and the rock shaft arethereby normally held by springs 35 at 10 the limit of their range ofoscillation through engagement with the respective stops 2|] and I9.

I When the rock shaft is oscillated from its position of rest, it firstsubjects the springs 35 to additional compression and the arrangement issuch that not until the rock shaft approaches the extreme of itsmovement in the other direction does the snap mechanism cross deadcenter to reverse the thrust on the actuator 25, thereby causing suchactuator to snap vigorously into engagement with the opposite stop.

Preferably, though not necessarily, the driver head 26 is madespool-shaped, as shown in Figure 10, with flanges which, in the extremepositions of the parts, enter the notches 31 in the terminal portions 36of the respective spring guide rods 34 (see Figure 2). The flanges onthe driver 26 extend the depth of the recesses 21 to guide the springguide rods and firmly seat against the driver even in the extremeposition illustrated 30 in Figure 2, the notches 31 affording sufficientclearance to permit of this increase in depth of the grooves 21.

To further insure against the release of the terminal portion of rods 34from the grooves 2'! 35 of the driver heads 26 I may provide the contactactuator stem 25 with up-turned arcuate flanges at 39 behind the ends ofwhich the terminal portions of the respective rods 34 engage in theirextreme positions, as shown in Figure 2.

40 The moving contact carrier floats free of the shouldered portions offlanges 28 under the pressure of a single compression spring 40 which isseated in a socket in the head portion 26 of the rock shaft l8. Sincethe pressure of compression spring 40 is centrally applied, and sincethe contact carrier is fully floating, it will automatically adjustitself to distribute the pressure of the spring to any three or lesspoints of engagement. In the form of contact carrier shown in Figure 3,

there are only two contacts 42 and accordingly the pressure of thespring acting on the contact carrier is thereby divided between thesetwo contacts. In the form of contact carrier shown at 29 in Fig. 8,there are three of the contacts 42 between which the pressure of thespring will be divided. Since three contacts will ordinarily serve toperform even the most complex switching operations, it will be obviousthat for all ordinary purposes the spring pressure may be equallydivided between the contacts.

Since the contacts disclosed are adapted to bridge two stationarycontacts or terminals, it will further be apparent that if one of theseterminals should be higher than the other, the

contact, if rigid, would be prevented from performance of its bridgingfunction since its engagement with the high terminal would hold it freeof engagement with the other.

Accordingly, in order further to divide the pressure of the singlespring, I have adapted the contacts 42 for individual pivotal movementabout fulcrurns intermediate their terminal portions. The constructionclearly appears in Figs. 3, 6, and 8. These particular contacts arepreferably in arcuate form and accordingly a strip of metal of arcuateform has its ends turned down as shown at 43 to pass through openings 44in the contact carrier 29, whereby the oscillation of the contacts 42with the contact carrier is as sured. These apertures 44 aresufficiently large so that they do not restrict the freedom of movementof the downwardly turned ends or prongs 43 of the contact 42. In orderto provide a fulcrum upon which the contact may tilt to adjust itselffor engagement with the fixed terminals or contacts, I preferably embossdownwardly each opposite marginal portion of the strip comprising thecontactor 42, thereby providing the fulcrum members 45 at opposite sidesof the intermediate portion of the contactor, the intervening area alongthe center line of the contactor being unchanged. It will be apparentfrom Fig. 6 that each one of the contactors 42 is free to oscillate uponits laterally disposed integral fulcrum bosses at 45 so that the endportions of its generally planiform contact surface may accommodatethemselves to the fixed terminals.

Fixed in the end of the switch barrel or casing IQ is the fixed contactcarrier or terminal head 48. Like the contact carrier 28, the fixedcontact carrier or terminal head 48 is made of dielectric material suchas fiber or bakelite. The particular disposition of the fixed contactsor terminals therein will, or course, depend on the particular functionfor which the switch is made. In the present device, the contacts arearranged in sets of three as clearly shown in Fig. 4, the two supplycontact rivets being designated by reference characters 49 and 50,respectively, and the output contact rivets being designated byreference characters 5|, 52, 53, and 54. The contacts 5| and 52 areconnected by a conductor 55 and the contacts 53 and 54 are connected byaconductor 56. It will be apparent that in one position of the contactcarrier 29 its bridge contacts 42 will respectively connect contacts 49and 5| at one side and contacts 50 and 54 at the other side. In theother position of the contact carrier 29, its bridge contacts 42 willrespectively connect terminal contacts 49 and 53 at one side and 52 and50 at the other.

In the snap action mechanism shown in Fig. 9 the compression springs 35instead of being seated at one end upon the flanges 2B of the contactactuator 25 are seated at both ends upon the shouldered portions ofT-shaped guide members having their respective stems overlapping withinthe springs. Each of the T-shaped guide memhere 58 has a head, the headof one being engaged in the groove 27 of the rock shaft 26 and the headof the other being engaged in a similar fulcrum recess provided at 59 inthe flanged end of the actuator 25. The compression spring 35 not onlytends to elongate the combined length of the spring guides 58 but alsoconfines their shank portions for relative sliding movement upon eachother. The operation of the snap mechanism shown in Fig. 9 is exactlythe same as that of the mechanism shown in Fig. 2. In either case analmost complete throw of the rock shaft occurs before the snap actionfunctions to displace the contact actuator. In the particularpreselective gear shifting device in which this switch is used, thisorganization makes it impossible for the contact actuator to functionprematurely and the arrangement insures that the remaining mechanism towhich the diaphragm i4 is connected will be in proper position beforethe switch operates.

It will further be apparent that each end of each of the bridgecontactors 42 on the carrier 29 must be in pressure engagement with thefixed contact rivet over which it lies. The pressure of the singlecompression spring 49 which acts on the carrier 29 is first dividedbetween the several bridge contacts 42 and then, by the oscillation ofthese contacts upon their respective fulcrums, the portion of springthrust allotted to each contact is divided between the ends thereof toinsure operative engagement with the terminal. This feature makes itunnecessary to support the ends of the several contacts with individualsprings and the construction and operation or" the switch is therebygreatly improved and rendered economical. The contacts 42, as shown indetail in Fig. 6, may be made up independently of other portions of theswitch mechanism for incorporation in this or other switches.

I claim:

1. In a switch, a rotatable disk comprising a contact carrier providedat intervals about its periphery with substantially radial notches, anda balanced series of contact elements on the face of said disk, eachelement having fulcrum means intermediate its ends and each elementproviding two contact surfaces and tongues engaged through said notches,the several elements being arcuate about the axis of said disk forpivotal movement upon substantially radial fulcrum axes.

2. In a switch, a substantially rigid contact comprising a strip ofmetal having a substantial- 1y planiform contact surface interruptedonly adjacent the margins of the strip by integrally formed marginalfulcrum bosses.

3. In a switch, a substantially rigid contact comprising a strip ofmetal having a substantially planiform contact surface interrupted onlyadjacent the margins of the strip by integrally formed marginal fulcrumbosses, the ends of said strip being bent substantially at right anglesto said contact surface to comprise guiding tongues.

l. In a switch, the combination with a contact carrier of insulatingmaterial provided with a face portion having openings, of a contactelement comprising a strip provided with fulcrum means intermediate itsends, contact surfaces at each side of said fulcrum means, and at leastone tongue projecting from an end of said strip into an opening of saidsurface to position said strip while accommodating its pivotal movementupon said fulcrum means.

5. The combination with a contact element comprising an arcuate stripprovided intermediate its ends with marginally disposed fulcrum means,said strip having contact surfaces at each side of said fulcrum meansand being provided therebeyond with integral tongues formedsubstantially at right angles to said strip, of a contact carrier havingmeans engaged loosely by said tongues to position the contact elementupon the face of the carrier while permitting the rocking movement ofthe contact strip upon said fulcrum means.

6. In a switch, the combination with a contactor comprising a contactactuator, a contact carrier and contact means mounted on said carrier,of a driver mounted co-axially with said actuator, stops limiting themovement of said driver and said actuator between predeterminedrespective positions, the driver having a peripheral notch, a springguide having a terminal portion seated in said notch and another portionengaging the contact actuator of said contactor, and compression springmeans carried by said guide and exerting its pressure oppositely uponsaid actuator and the notched peripheral portion of said driver.

7. In a switch, the combination with a socketed driver mounted foroscillation, of a co-axially oscillatable contact actuator, a contactcarrier connected for oscillation with said actuator, a spring seated inthe socket of said driver and bearing on said carrier, contact meansmounted on said carrier, a terminal head providing complementary contactmeans with which the contact means of the carrier is cooperative, andsnap action mechanism operatively connecting said driver with saidactuator for the delayed snapping operation of the actuator upon thecompletion of a predetermined movement of the driver.

ROBERT K. WINNING.

